1. Field of the Invention
The invention relates to actuating mechanisms such for example as those devices used for key switches and to key switches which are utilized with reconfigurable keyboards. With still more specificity the invention relates to a key switch for a reconfigurable photo optical keyboard having a novel shift lock mechanism utilizing a C-shaped single turn torsion spring.
2. Description of the Prior Art
Prior art keyboard key switches generally utilize coiled springs one end of which (generally the bottom end of the spring) is secured to a base support member while the opposite end is secured to a movable portion of the key switch. This construction requires an upper and a lower attachment as well as some means to retain the key stem from falling out of the bottom of the base structure assembly. Usually this structure is the bottom or baseboard of a keyboard. Replacement rearrangement or service of this type of key and keyboard arrangement requires special tools and is time consuming and inefficient. Also, key switches of the prior art are generally relatively complicated in their construction and those that have shift lock elements are fairly complex in their structural elements and require relatively large amount of tooling to fabricate and to insert into the keyboard, often requiring considerable hand work.
Other keyboard systems of the prior art produce wear characteristics which are highly undesirable both with respect to the shift lock mechanism as well as with respect to the key depression itself. And, importantly, prior art designs require separate switch bodies and individual structural combinations for utilizing a specifically designed key shift lock which increases the cost and complexity of assembly and tend to decrease efficiency by increasing the risk of failure due to increase in the number of parts and wear surfaces.
This application is related to application U.S. Ser. No. 124,945, now U.S. Pat. No. 4,301,345 filed Feb. 26, 1980 in the name of Justin O. Balta, Entitled "Key Switch Actuation By Torsion Spring" and assigned to the present assignee.